The release notes in 0.44 explain it and reference the requests:
* handling of the par2 in obfuscating posts [https://www.altbinz.net/forum/requests/rename-differently-named-parity-files-to-same-name-so-they-can-be-used-to-repair/]
+ option to autorename video file to collection name (Setup->Unrar->Auto rename movie file to collection name) (default on) [https://www.altbinz.net/forum/requests/rename-unrar'd-file-to-match-nzb-release-name/]
Basically, several indexers post files using various obfuscation methods which meant prior to rdl making the changes, the parity files would be named something random and unable to be used without renaming them.
Also, once the file was extracted from the obfuscated posts, the file name was random characters .mkv and another change was made to allow an optional rename the .mkv file as per the nzb file.
Obviously not all indexers post their own content, but those that do, are posting in an obfuscated manner and since these changes were implemented, downloading those obfuscated files now is as easy to deal with as plain text files.
Hope that explains it.